From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH V4 27/28] PCI: tegra: Add support for GPIO based PERST# References: <20190613152404.GB30445@e121166-lin.cambridge.arm.com> <20190614143222.GB23116@e121166-lin.cambridge.arm.com> <1508173d-0ecc-f498-6ab2-78a718086b35@nvidia.com> <20190614145023.GA24588@e121166-lin.cambridge.arm.com> <20190614152304.GK15526@ulmo> <20190614155934.GA28253@e121166-lin.cambridge.arm.com> <51e4ae62-f842-1d2f-fbca-0b2063dd53a6@nvidia.com> <20190614165353.GB30511@e121166-lin.cambridge.arm.com> <1c662f82-8329-5e1b-58bf-b2fe1643adb0@nvidia.com> <20190617094839.GE18020@e121166-lin.cambridge.arm.com> From: Manikanta Maddireddy Message-ID: <0f9bb97d-5a30-a654-0cc6-a57a7bd894c8@nvidia.com> Date: Mon, 17 Jun 2019 15:57:09 +0530 MIME-Version: 1.0 In-Reply-To: <20190617094839.GE18020@e121166-lin.cambridge.arm.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Language: en-US To: Lorenzo Pieralisi Cc: Thierry Reding , bhelgaas@google.com, robh+dt@kernel.org, mark.rutland@arm.com, jonathanh@nvidia.com, vidyas@nvidia.com, linux-tegra@vger.kernel.org, linux-pci@vger.kernel.org, devicetree@vger.kernel.org List-ID: On 17-Jun-19 3:18 PM, Lorenzo Pieralisi wrote: > On Fri, Jun 14, 2019 at 10:53:13PM +0530, Manikanta Maddireddy wrote: > > [...] > >>> Ok. My point then is that you have no way to enforce this requirement on >>> platforms that actually need it, I do not even know if there is a >>> way you can do it (I was thinking along the lines of using a >>> compatible string to detect whether the GPIO #PERST reset is mandatory) >>> but maybe this is not even a SOC property. >>> >>> Maybe what I am asking is overkill, I just wanted to understand. >>> >>> I was just asking a question to understand how you handle the case >>> where a GPIO pin definition is missing in DT for a platform that >>> actually needs it, the driver will probe but nothing will work. >>> >>> It would be good to describe this and capture it in the commit log. >>> >>> Thanks, >>> Lorenzo >> I can't think of a easy way to enforce this requirement. As you said >> compatible string is per SOC, so we can't use it for a platform. >> This issue is present on only one platform, so it is hard to miss the >> DT property. That is the reason for publishing this patch with out this >> enforcement in driver. >> >> I thought for changing PERST# to GPIO for all platform, but testing is >> a tedious job. Also I don't have Tegra20 and Tegra30 platforms. > I can't help with that. > >> Do you want me to drop the patch or update the limitation in the commit >> log? > It is Thierry's call, if he is OK with it fine by me, please do > update the commit log, it will help everybody understand. > > Lorenzo Sure, I will update the commit log in V5. Please let me know if you completed reviewing this series, I will send V5 addressing review comments in this patch. Manikanta